This invention pertains to the field of semiconductor laser fabrication and more particularly to the application of laser radiation in said fabrication.
An article entitled "Unstable Horizontal Transverse Modes and Their Stabilization with a New Stripe Structure", IEEE J. Quant. Elec., Vol. QE-13, No. 8, August 1977, pp. 659-661, by K. Kobayashi, R. Lang, H. Yonezu, Y. Matsumoto, T. Shinohara, I. Sakuma, T. Suzuki, and I. Hayashi discloses that the active region of a laser-diode has to form a channel waveguide not more than 5 microns wide for single-mode operation. In fact, as shown in an article entitled "GaAs-Ga.sub.1-x Al.sub.x As Buried-Heterostructure Injection Lasers", J. Appl. Phys., Vol. 45, No. 11, November 1974, pp. 4899-4906 by T. Tsukoda, the best single-mode AlGaAs/GaAs laser-diode has a mesa type structure which is only about 1 micron wide. The mesa type of structure shown in the Tsukoda article and known by those skilled in the art as a buried structure requires a two-step growth process and is difficult to fabricate.